The point is that they aren't especially proven and Brewer is only an upperclassmen because we didn't have the luxury of redshirting him. It wasn't like there was a real 2-deep at TE this season with Brewer recovering from injury. Leitao didn't play a snap at the position. I haven't heard much buzz about any of the returning TEs. At least on the OL there was talk that Imade, Angilau, and Jones are making moves. Hit on 2 of those and the OL could be decent even without a GT, assuming they stay healthy. We are set at QB and WR and while our RB room is thin, Ingram is a proven plus asset.
I hope the position works out with the current roster, it is normal for there to be an unknown when a proven senior leaves the team. I am just pointing out that for all the handwringing about who we should be chasing as a grad transfer, including positions that have some proven depth like DL, TE is a position of potential concern that no one wants to talk about.